The effects of major transitions on children's psychological adjustment are investigated. Children are studied across the year of transition from elementary school to middle school and junior high school, which coincides with the period of transition from childhood to early adolescence. The focus is on children's reports of their self-concept and self-esteem and on reports from their teachers and peers. Analyses examine normative adjustment in a sample of 445 children as well as the psychological profiles of subgroups at risk because of low self-esteem, poor self-concept, isolation, or aggressive tendencies--all factors that are implicated in behavioral disorders in adolescence.